I'm building a setting for a sci-fi RPG. The overall idea is a somewhat grounded in reality universe, albeit impractical and honestly quite silly sometimes.

Somewhat like Shadowrun meets Futurama.

In this setting, one of the world-sprawling corporations is a food-based company called CHECKERS.

CHECKERS has, as one of its signature services, the Orbital Delivery. You open up an app on your smartphone, select your goods, pay the fee, and in a little bit a package is sent your way from their space-based wharehouse (employment laws are a tad more lax in low earth orbit).

This service is mostly used to deliver shady packages all over the globe - weapons, ammo, legally-questionable devices, underpaid software developers... you name it. However, this highly-questionable service can't be used in the open without attracting attention from all sorts of governments, so CHECKERS needs a good coverup to their operation.

They solved it using Orbital Delivery Pizza.

CHECKERS puts its pizzas - while still uncooked - inside a specially designed shell and shoots it down from orbit towards the target destination. The pizza-boxes use the heat from re-entry to cook their contents, delivering its cargo hot and crispy down there. Sometimes too crispy.

Those containers are - externally, at least - almost indistinguishable from the packages containing the shady goods. To the layman, seeing an orbital package usually means their fellow friendly neighbor ordered a nice pepperoni pizza. To the neighbor, getting that package means that they just got their weekly fix of Gethighnow 20x or similar. So far so good.

This, however, raises a question - Is the heat from re-entry enough to cook a pizza? Is it even possible to build a container able to capitalize that heat and cook the pizza inside?

6 Answers
6

If you’re designing the delivery system however you like? Sure. Just drop it in a normal (ie large enough for significant compressive heating to occur) capsule and have a cooling loop between the nose cone and an oven inside. Angle the descent so you have at least enough heating time for the pizza, only turn on the loop when the temperature outside is above the internal oven temperature and turn it off when the oven is hot enough.

Perfectly cooked pizza every time, as long as it has a short enough cooking time (as good pizzas should).

The better question is why do this? It would be smaller, simpler easier and more efficient if you cooked the pizza in orbit with an electric oven (using your abundant solar power. You have that right?) then used a small rocket motor to deorbit a small insulated box with a parachute attached.small light box means you need less shielding which means less delta v which means less fuel wasted on the deorbit burn.

Hell, if you want to: cook the pizza using waste heat from the booster you’re using to de-orbit the delivery box. That way it’s possibly the most efficient and every pizza comes with a lovely aftertaste of literal rocket fuel.

Yes, you can. But it will be very, very tricky to do. And also extremely expensive to develop. If you want to develop an orbital pizza delivery system, steer away, there are far better ways to make money.

Reentey can generate temperatures of around 1650°C (3000°F) and takes anywhere from 30 minutes to just over 10 depending on your space craft. Say you have the most high tech heat diffusers keeping your temperature at a nice even 200°C, and your reentry takes no longer than 20 minutes, then yes, your pizza will still be burnt. Most heat dissapation takes place after reentry, as the heat is absorbed by the heat shield. So for a fair amount of time your orbital oven will stay quite hot, cooking your pizza with residual heat. As reducing the temperature further will give you a slab of warm dry rubber instead of a pizza, you will need to reenter quicker. Which most likely generates more heat, so better shielding is needed, which is more volatile. And your pizza will most likely still be overcooked.

All in all, in theory, it might be possible. But you'll most likely end up with overcooked pizza and crushed hopes and dreams. A better approach would be to take the fuel out of the boosters you will need, and use it to power an oven. You could bake dozens (if not hundreds) of pizzas with it, and put in a lot less effort and money.

$\begingroup$It's actually pretty easy to reduce the heat of reentry: just get your de-orbiting delta-V some other way than air-braking. In the extreme case if you reduce your orbital speed to zero before reentry (via rockets or railgun or what have you) your payload will just fall at terminal velocity with very little heat generated.$\endgroup$
– GeneFeb 26 at 23:32

$\begingroup$I'm not sure the expense of development is a big deal, the pizza delivery is a subterfuge for presumably far more valuable (and therefore expensive) contraband drops.$\endgroup$
– T.J.L.Mar 9 at 20:52

Given that you need special thermal ablative to not cook passengers, I would say it's even more then enough heat to cook pizza. You can re-enter in many different angles, so you could pick baking time even.

$\begingroup$Indeed... if by "cook" you mean "incinerate to ash", then yes, there is enough heat 😉. Except that you might have trouble exposing it to heat for long enough...$\endgroup$
– MatthewFeb 26 at 15:55

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$\begingroup$@Matthew: you could design the box so that it absorbs heat during re-entry and distributes that heat slowly and evenly to the pizza; that way the pizza would complete cooking after it landed. Seems like an awful lot of trouble to go through to get a pizza, though.$\endgroup$
– Ted WrigleyFeb 26 at 16:09

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$\begingroup$As a former pizza cook in the part of Florida where we could see the shuttle going up, I feel uniquely qualified to provide some additional data point. Our Pizzas would be cooked in an oven at about 400-475 F for 8-10 minutes time. The Orbiter (the part of the shuttle that looks like a plane, the entire stack is "the Shuttle" according to NASA) on reentry will experience temps of ~ 3000 F for about 3 minutes to 30 minutes depending on approach (pre-Shuttle was about 3:15 minutes (straight dropped) while the shuttle was closer to 30 minutes (gliding to landing).)+$\endgroup$
– hszmvFeb 26 at 18:13

$\begingroup$+This would be a temperature and time would be more than enough to not only cook my pizza, but melt my oven to slag to boot. The temperature is also sufficient enough to melt the aluminum frame of the shuttle if left unshield, which was what ended Columbia (the shield break was in the under wing, which compromised the wing and caused the oribiter to go into a violent barrel roll spin, breaking it apart). For a reference, 3000 F is about 1780 F hotter than the melting point of aluminum, which is the metal used in the shuttle's frame.+$\endgroup$
– hszmvFeb 26 at 18:23

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$\begingroup$Because it's so hot, most people don't quite get how hot it can be. Rest assured, I, your pizza space man have seen the heat resistent tiles in action, up close and personal (the white ones, which don't resist heat nearly as well as the black ones). NASA does have a "used" tile on hand and I was once selected to demonstrate their resistence by placing my then sixth grade aged hand on the tile while the tech hit the other side of the tile with a blow torch. My end remained cool to the touch (I however was not cool as no one asked "are you afraid of fire")+$\endgroup$
– hszmvFeb 26 at 18:28

$\begingroup$Presumably the "shady cargo" capsules can have a different internal design from the pizza-cooking capsules. They just need to look the same on the outside. (The catch, actually, is that they will need to have similar mass, or someone will notice that some capsules have inexplicable flight characteristics.)$\endgroup$
– MatthewFeb 27 at 15:55

As a former pizza cook in the part of Florida where we could see the shuttle going up, I feel uniquely qualified to provide some additional data point. Our Pizzas would be cooked in an oven at about 400-475 F for 8-10 minutes time. The Orbiter (the part of the shuttle that looks like a plane, the entire stack is "the Shuttle" according to NASA) on reentry will experience temps of ~ 3000 F for about 3 minutes to 30 minutes depending on approach (pre-Shuttle was about 3:15 minutes (straight dropped) while the shuttle was closer to 30 minutes (gliding to landing)). Angle of re-entry is important as the shuttle's glide meant it had to take a shallower angle, where as the Apollo and earlier had a much steeper angle of re-entry... this is somewhat covered in the conclusion of Apollo 13, with the longer period it took to re-establish communications (nearly double the time of typical Apollo missions), because they had a much shallower re-entry angle owing to the fact that much of the planned mission had to go out the window. The window for descent had to be changed to get them down earlier.

This would be a temperature and time would be more than enough to not only cook my pizza, but melt my oven to slag to boot. The temperature is also sufficient enough to melt the aluminum frame of the shuttle if left unshield, which was what ended Columbia (the shield break was in the under wing, which compromised the wing and caused the oribiter to go into a violent barrel roll spin, breaking it apart). For a reference, 3000 F is about 1780 F hotter than the melting point of aluminum, which is the metal used in the shuttle's frame. And itt may only be by 800 F less then re-entry heat, but even lava is cooler!

Because it's so hot, most people don't quite get how hot it can be. Rest assured, I, your pizza space man have seen the heat resistant tiles in action, up close and personal (the white ones, which don't resist heat nearly as well as the black ones). NASA does have a "used" tile on hand and I was once selected to demonstrate their resistence by placing my then sixth grade aged hand on the tile while the tech hit the other side of the tile with a blow torch. My end remained cool to the touch (I however was not cool as no one asked "are you afraid of fire").

That said, looking back, it should be a point of knowledge that NASA educators felt comfortable to hold a lit blow torch that close to a child's hand and not get sued by the absent parents. So your exposed pizza would be basically be vaporized while your properly shielded for re-entry oven would be a cool as an uncooked pizza when it landed. And I should point out that you should not be allowed in a kitchen if you think raising the heat will lower the cook time at the same ratio. Ovens do not work that way.

First of all, it would not work at all. The box would melt, yes, but then the contents inside would melt too. Unless you can put a heat-resistant shield on the actual shell, of course. Maybe before it lands, a parachute will be deployed so that the item inside lands softly.